Proton modified Pt zeolite fuel cell electrocatalysts

Abstract

NaY zeolite has been selected as a suitable material to host 1.5 wt.% platinum (Pt) loading on zeolite using ion-exchange methods of Pt(NH3)4(NO3)2 without excess NH4NO3 nitrate and Pt(NH3)4(NO3)2 with excess NH4NO3 nitrate. The structure/reactivity relationship of Pt nanoparticle was experimentally studied via Nafion@-bound electrodes to investigate the interaction nature of Pt with zeolite and electron transfer. By using extended X-ray adsorption fine-structure (EXAFS) technique, Pt particle size was predicted as 0.7-1.5 nm. It was found Pt oxides could be electrochemically reduced via a hydrogen 'spillover' phenomenon. A highly dispersed small Pt particle distribution can be achieved with excessive H+ ions on zeolite acidic sites.